[FS#1299] Build system can't build target-specific packages depending on generic packages

[LEDE Bugs]

A new Flyspray task has been opened.  Details are below. 

User who did this - Carl-Daniel Hailfinger (hailfinger) 

Attached to Project - OpenWrt/LEDE Project
Summary - Build system can't build target-specific packages depending on generic packages
Task Type - Bug Report
Category - Toolchain
Status - Unconfirmed
Assigned To - 
Operating System - All
Severity - Low
Priority - Very Low
Reported Version - Trunk
Due in Version - Undecided
Due Date - Undecided
Details - Device: Arcadyan / Astoria VGV7510KW22 o2 Box 6431

Version: Latest openwrt snapshot (2018-01-25)

Steps to reproduce:
Look for the package asterisk13-chan-lantiq in the following locations:
https://downloads.openwrt.org/snapshots/targets/lantiq/xrx200/packages/
https://downloads.openwrt.org/snapshots/packages/mips_24kc/telephony/
Neither location contains the package asterisk13-chan-lantiq. asterisk13-chan-lantiq is special because it both depends on asterisk (which is built as generic telephony package) as well as kmod-ltq-vmmc (which is built for the lantiq/xrx200 family of devices).

Cross-references:
https://github.com/openwrt/telephony/issues/193
https://github.com/openwrt/telephony/pull/199

More information can be found at the following URL:
https://bugs.openwrt.org/index.php?do=details&task_id=1299